Steam-boiler and furnace



(No Model.)

0. R. 86 G. A. AYER. STEAM BOILER AND PURNAGE.

Pate nted May 30, 1893 NVENTI: 5-

[n45 mama PETERS cc. PNOTO-LITNQ, WASHINGTON, n. c

UNITED STATES PATENT OFFICE.

cALEB R. AYER, OF BOSTON, AND GEORGE AYER,IoF WORCESTER,

MASSACHUSETTS.

STEAM-BOILER AND FURNACE.

SPECIFICATION forming part of Letters Patent No. 498,500, dated May 30, 1893.

Application filed May 6, 1892. Serial No. 431,999. (No model.)

To aZZ whom it may concern:

Be it known that we, CALEB R. AYER, of Boston, in the county of Suffolk, and GEORGE A. AYER, of Worcester, in the county of Worcester, State of Massachusetts, have jointly invented certain new and useful Improvements in Steam-Boilers and Furnaces, of which the following, taken in connection with the accompanying drawings, is a specification.

Our invention is a cylindrical tubular boiler, one feature of improvement being the combination with the boiler shell of a substantially tubular steam drum in immediate contact with and riveted longitudinally to the upper portion of said shell, communication between them being made through a series of perforations. The drum is somewhat flattened or concaved along the line of junction, and the riveting is preferably internal or concealed from view. The boiler shell is strengthened by stay rods where perforated, and elsewhere by cross stays from the outer to the inner walls.

Our boiler is of the down-draft water-tube type, the water-grate descending from the water wall below the feed door to a transverse water-box independent of the side, water-containing Walls, such box receiving its supply of Water from the lower portion of the surrounding water-wall through short radial tubes. Adjoining this transverse box, through which all the grate tubes are supplied with water, is a water-leg connected to the side walls of the fire-box, closing the inner end of the fuel chamber, and serving to deflect the caloric current downwardly through the grate. This current, after passing beneath said leg rises among the numerous water tubes with which the boiler shell is filled, passes over the upper edge of the same leg, and is deflected downwardly by another water leg standing across its path as the current returns toward the front upper part of the shell, there to enter the uptake and pass off. The current thus impinges against the walls of the boiler and the surfaces of the water legs with great efficiency. The longitudinal water-tubes extend, by means of sleeves or thimbles, through these transverse Water legs, the caloric current passing such tubes chamber I-l below the grate.

three times and impinging upon them, with much heating effect, at each passage. The tubes have an inclined position so that circulation from rear to front is constant. One range of these tubes forms, with a fire-brick backing, the roof of the fuel chamber or firebox proper, the fire-brick running back only to the first Water-leg. From the upper part of the shell a water or steam pipe passes directly through the uptake into the steam drum, its contents being materially heated in such passage. The. end walls of the boiler shell are furnished with screw caps opposite to the end of each water tube, to give access thereto if required. These end walls are in an oblique position, at right angles to the inclined water tubes. Between the outer and inner end-walls and side-Walls are ample water spaces, supplying water for conversion into steam by the heat appliedin the fire-box and by the caloric current deflected as stated and impinging on the interior of said walls and the exterior of said tubes. Hand-holes through the side walls permit clearing off the tubes.

In the drawings, Figure l is a longitudinal vertical section through our improved boiler. Fig. 2 is an end view, partlyin vertical transverse section.

A represents theouter peripheral wall of the boiler shell, and B the inner shell, parallel to the wall A and stayed thereto at frequent intervals by transverse bolts or rivets. C O and D D are respectively the ends of these cylinders A B, the water walls or spaces inclosed between them being indicated by the letter E.

F denotes the succession of oblique, longitudinal water pipes which, thickly set, extend from end to end of the boiler being severally expanded in the heads or end plates D D and affording watercommunication between the end water-Walls E. A screw cap G, is provided in each head 0 O opposite to the end of each tube F, to give access in setting or repairing it.

The fire box iscomposed of the fuel chamber I-l, above the grate I, and the combustion The grate consists of a series of parallel water tubes I, all connected with the front water wall E and with a transverse water box J parallel to said wall at the inner end of the fuel chamber. This water box is supplied with water from the lower portion of the peripheral water-wall through radial or upright pipes K, and the water so supplied rises Y through the grate tubes to the front wall E, and thence upwardly as the circulation requires. The grate tubes are inclined upwardly from the box J to the water-wall, about parallel to the waterpipes F.

The fire box has the feed door and draftopening L above the grate, and the combustion chamber has a door M for removal of ashes. The draft is downwardly through the mass of fuel upon the tubular grate, there being at the inner end of the fuel chamber the transverse water leg or wall N extending from side to side of the inner shell B of the boiler, the hollow interior of said leg or wall communicating at each of its ends with the peripheral water-walls of the boiler. This transverse leg or wall N occupies an approximately central position in the boiler, first deflecting the caloric current downwardly, beneath its lower edge, which is adjacent to the water-box J, and then causing the current to rise among and impinge upon the several water pipes F, until such current escapes over the upper edge of said wall N and strikes another transversew leg 0, depending from the upper wall of the inner shell B. This deflects the current again downwardly, causing it to pass the several tubes a second time, after which it rises, passing them a third time and reaching the uptake P.

The water tubes F, as stated, run from end to end of the inner shell B. In so doingthey pass through the transverse wall N or leg 0, some of them through both these barriers, as seen in Fig. 1. Sleeves or thimbles Q are provided for the tubes to pass through. One range of these tubes forms, with a fire-brick backing R, the roof of the fire-box. This range of tubes is heated by the direct action of the'fire upon the grate, and by conduction from the fire-brick backing R. The tubes below this range extend'only from the water wall- N to the rear wall E.

The steam chamber for our boiler is a nearly cylindrical drum S, flattened or concaved along its lower face and lying lengthwise upon and riveted directly to the outer shell A. The drum S has its edges turned inwardly so as to be secured internally and bya double line of rivets T to the shell A, thus affording a simple, strong and desirable fastening, well resisting the steam pressure. Communication between the shell and drum is through a series of elongated transverse apertures V through the boiler shell. At each of these apertures a transverse stay-rod U is furnished, running internally directly across within the shell A and serving to strengthen it where the aperture had weakened it. Between the several apertures are broader portions of the boiler plate not perforated or at all weakened. The water line will usually be above the junction of the shell and drum. A dry-pipe to draw steam from is shown at W, and a manhole for the workman at X, Fig. 1.

The uptake P being near the front end of the boiler, in front of the second leg 0, we provide an outlet for steam or highly heated water, from the top of the front end-wall E into the drum or steam chamber S, such outlet consisting of an enlarged pipe Y passing directly through the uptake, where the caloric current is utilized again to impart its heat to the water or steam within the pipe.

Hand-holes Z,Fig. 2, may be formed through the boiler shell, giving lateral access to the tubes F, so that ashes accumulated thereon may be blown away or otherwise removed. With the downward draft no soot accumulates, such matter being consumed in the firebox.

We claim as our joint invention-' 1. In a down-draft steam boiler, a water grate connected at its front end with the water wall of the boiler and descending obliquely therefrom, in combination with a transverse water box with which the inner ends of the grate tubes communicate, said box receiving its water supply from the lower parts of the peripheral water wall through radial connecting pipes, substantially as set forth.

2. In a down-draft steam boiler, the combination of a water jacket and water end-walls with a multiplicity of internal water tubes connecting said end-walls, among which tubes the caloric current passestransversely thereof, and with a transverse water leg and a firebrick roof-plate for the fuel chamber, serving to deflect such current downwardly through the grate, substantially as set forth.

3. In a down draft steam-boiler, the combination of a water-jacket and water-containing end walls with a multiplicity of inclined water tubes among which the caloric current circulates, and with two or more water legs or transverse walls in the path of the current, serving to deflect it against said tubes, substantially as set forth.

4.. In a down-draft steam boiler, end and peripheral water-walls, transverse water-legs or walls and a series of longitudinal water pipes, in combination with sleeves or thimbles in said transverse legs or walls through zvhich said pipes pass substantially as set orth.

5. In a down-draft steam boiler, a cylindrical boiler shell, having end and peripheral water walls, an inclosed fire box, and a transverse water leg at the rear end of the fire box, serving to deflect the caloric current downwardly and against the bottom and rear water wall, in combination with a substantially cylindrical steam drum, mounted upon and riveted directly to said cylindrical shell, and with a succession of openings through said shell into said drum, substantially as set forth.

6. In a down-draft steam boiler, end and peripheral water walls, inclined water tubes 5 connecting said end walls, and a down-draft fire box, inclosed between such walls, in combination with transverse water legs, deflecting the caloric current to the uptake at thefront of the boiler, a steam drum above said I0 boiler in rear of the uptake, anda steam pipe from the top of the front water wall to said 

